Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/26—Folded plies
  • B60C9/263—Folded plies further characterised by an endless zigzag configuration in at least one belt ply, i.e. no cut edge being present
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/005—Reinforcements made of different materials, e.g. hybrid or composite cords
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/1807—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers comprising fabric reinforcements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C2009/2012—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel with particular configuration of the belt cords in the respective belt layers
  • B60C2009/2032—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel with particular configuration of the belt cords in the respective belt layers characterised by the course of the belt cords, e.g. undulated or sinusoidal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/26—Folded plies
  • B60C9/263—Folded plies further characterised by an endless zigzag configuration in at least one belt ply, i.e. no cut edge being present
  • B60C2009/266—Folded plies further characterised by an endless zigzag configuration in at least one belt ply, i.e. no cut edge being present combined with non folded cut-belt plies
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C2200/00—Tyres specially adapted for particular applications
  • B60C2200/02—Tyres specially adapted for particular applications for aircrafts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/0007—Reinforcements made of metallic elements, e.g. cords, yarns, filaments or fibres made from metal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/0042—Reinforcements made of synthetic materials

Definitions

• the present invention relates to a tire for aircraft and, in particular, a tire crown reinforcement for aircraft.
• the circumferential, axial and radial directions respectively designate a direction tangent to the running surface of the tire in the direction of rotation of the tire, a direction parallel to the axis of rotation of the tire and a perpendicular direction. to the axis of rotation of the tire.
• radially inner, respectively radially outer is meant “closer or more distant from the axis of rotation of the tire”.
• axially inner, respectively axially outer is meant “closer or more distant from the equatorial plane of the tire", the equatorial plane of the tire being the plane passing through the middle of the running surface of the tire and perpendicular to the tire. rotation axis of the tire.
• a tire comprises a tread intended to come into contact with a ground via a rolling surface, the tread being connected by two sidewalls to two beads, the two beads. being intended to provide a mechanical connection of the tire with a rim on which the tire is mounted.
• a radial tire for aircraft more particularly comprises a radial carcass reinforcement and a crown reinforcement, as described, for example, in document EP 1381525.
• the radial carcass reinforcement is the reinforcing structure of the tire connecting the two beads of the tire.
• the radial carcass reinforcement of an aircraft tire generally comprises at least one carcass layer, each carcass layer consisting of reinforcements, most often textile, coated in a polymeric material of elastomer or elastomeric type, parallel to each other and forming, with the circumferential direction, an angle of between 80 ° and 100 °.
• the crown reinforcement is the reinforcing structure of the tire radially inner to the tread and at least partly radially. outside the radial carcass reinforcement.
• the crown reinforcement of an aircraft tire generally comprises at least one crown layer, each crown layer consisting of reinforcements parallel to each other and embedded in a polymeric material of elastomer type or elastomeric mixture.
• the top layers there is usually a distinction between the working layers, which constitute the work reinforcement and most often constituted of textile reinforcements, and the protective layers constituting the protective reinforcement, consisting of metal or textile reinforcements, and arranged radially outside the working frame.
• the working frame conditions the overall mechanical behavior of the crown reinforcement, while the protective armature essentially protects the working layers from aggressions that can propagate through the tread radially inwardly of the tire.
• the textile reinforcements of the carcass layers and crown layers are most often cables consisting of textile filament yarns, preferably of aliphatic polyamide or aromatic polyamide.
• the mechanical properties in extension, such as the modulus of elasticity, the elongation at break and the breaking force of the textile reinforcements, are measured after prior conditioning.
• "Prior conditioning” means the storage of textile reinforcements for at least 24 hours, before measurement, in a standard atmosphere according to European Standard DIN EN 20139 (temperature of 20 ⁇ 2 ° C, hygrometry of 65 ⁇ 2%). The measurements are carried out in a known manner using a ZWICK GmbH & Co (Germany) type 1435 or type 1445 traction machine.
• the textile reinforcements are pulled over an initial length of 400 mm at a nominal speed of 200 mm / min. All results are an average of 10 measurements.
• a working layer is most often obtained by a circumferential winding zigzag or by a winding circumferential in turns of a strip, on a cylindrical laying surface having for axis of revolution the axis of rotation of the tire.
• the strip generally consists of at least one continuous textile reinforcement coated in an elastomeric mixture and, most often, a juxtaposition of continuous textile reinforcements, embedded in an elastomeric mixture and parallel to each other.
• the working layer is then constituted by the juxtaposition of strip portions.
• the advantage of having a zigzag circumferential winding or a circumferential winding in turns is to avoid, at the axial ends of the working layers, the presence of free reinforcement ends, likely to generate cracks in these zones and therefore, to decrease the endurance of the frame and the life of the tire.
• circumferential winding in turns of a strip means a winding of the strip, in the circumferential direction, and in a helix having a radius equal to the radius of the cylindrical laying surface and a mean angle, with respect to the circumferential direction, between 0 ° and 5 °.
• the working layer thus obtained by a winding in turns is called circumferential, because the angle of the two parallel textile reinforcements of the strip, formed in the equatorial plane with the circumferential direction, is between 0 ° and 5 °.
• circumferential winding zigzag a strip is meant a winding of the strip, in the circumferential direction, and in a periodic curve, that is to say a curve formed of periodic corrugations oscillating between extrema .
• Rolling up a strip according to a periodic curve means that the average line of the strip, equidistant from the edges of the strip, coincides with the periodic curve.
• the average line of the strip forms, with the circumferential direction of the tire and in the equatorial plane of the tire, an angle of at least 8 ° and at most equal to 30 °.
• each working layer form, with the circumferential direction of the tire and in the equatorial plane of the tire, an angle of at least 8 ° and at most equal to 30 °.
• the working layers are laid in pairs, each pair of working layers constituting a working bin.
• a working bin is constituted, in current zone, that is to say outside its axial ends, by two radially superimposed working layers.
• a working binappe At its axial ends, a working binappe generally comprises more than two layers radially superimposed.
• Axial end allowance is the number of additional working layers, in the radial direction, relative to the two working layers of the current area of the working bin.
• This axial end allowance is generated by the crosses of the strip at the end of working bin at each winding turn zigzag.
• Such a working frame comprising working pairs obtained by a zigzag circumferential winding of a strip has been described in the documents EP 0240303, EP 0850787, EP 1163120 and EP 1518666.
• thermomechanical stresses are very high, during the crushing and rolling of the tire, under the conditions of use of an aircraft.
• an airliner tire may be subjected to a nominal pressure greater than 15 bar, a nominal load greater than 20 tons and a maximum speed of 360 km / h. This results in a significant heat dissipation and therefore a high temperature level likely to limit the performance of the tire in endurance.
• the endurance performance of an aircraft tire is generally measured on an elementary qualification test, such as the TSO test (Technical Standard Order) imposed by an FAA (Federal Aviation Administration) standard.
• TSO test Technical Standard Order
• FAA Federal Aviation Administration
• the TSO test is a test performed on the steering wheel which is broken down into 4 phases: -50 take-off cycles of the aircraft, in which the tire is subjected to the nominal pressure P v and to a load varying between the nominal load Z n and 0.
• the objective of the TSO test is to perform all cycles without damage to the tire, the tire break-off, that is to say the loss of the tread, being allowed however during the last cycle, but not the loss of pressure.
• circumferential reinforcements for the working layers, that is to say of reinforcements forming a zero angle with the circumferential direction, which can lead to a drop in rigidity of the tire drift and a poorer control of its inflated profile centrifugal.
• the inventors have set themselves the objective of improving the endurance of the working frame of a tire for an airplane, by reducing the stresses thermomechanical at the axial end thicknesses of the working binaxes, constituting the reinforcement of work.
• an aircraft tire comprising:
• the working armature comprising at least one working bin, constituted at least in part by two radially superposed working layers,
• each working layer comprising reinforcements, embedded in an elastomeric material, positioned circumferentially in a periodic curve and forming, with the circumferential direction of the tire and in the equatorial plane of the tire, an angle of at least 8 ° and at most equal to at 30 °,
• the most radially inner working bin having the greatest axial width and comprising two axial ends, each corresponding to the most axially outermost and the most radially inner point of the working bin,
• the axial end of the most radially inner working binappe that is to say the most axially outer point, and the point of the most radially inner working binappe, positioned axially at the inside of said axial end at a distance L equal to 25 mm, are positioned radially outside the most radially outer carcass layer at respective distances D and D 'at least equal to minimum values.
• the distance D between the axial end of the radially innermost working bundle and its orthogonal projection on the radially outermost carcass layer is at least 8 mm.
• the angle A is the angle formed by the straight line passing through the axial end of the binappe and the point of the binapple, positioned 25 mm axially inwards, and the straight line passing through their respective orthogonal projections on the carcass radially outermost.
• the distance D between an axial end of the most radially inner working binappe and its orthogonal projection on the outermost radially carcass layer is advantageously at most equal to 16 mm. This maximum value reduces the risk of appearance of the axial end of the working bin on the surface of the tire, in case of wear of the axial end portion, or shoulder, of the tread.
• This maximum value also reduces the risk of appearance of the axial end of the working bin in case of wear of the axial end portion, or shoulder, of the tread.
• Reinforcements of the working layers of any working binappe are preferably made of a textile material. The textile guarantees a good compromise between the mass and the breaking strength of the reinforcements.
• textile reinforcements for any working bin, that is to say for all working layers, allows a significant contribution to the minimization of the mass of the tire, and therefore to the payload gain of the aircraft .
• textile reinforcements commonly used in aircraft tires there are the reinforcements consisting of an aliphatic polyamide, such as nylon, and reinforcements consisting of an aromatic polyamide, such as aramid.
• the aromatic polyamide reinforcements have a compromise between the mass and the breaking strength better than that of the aliphatic polyamide reinforcements.
• the reinforcements of the working layers of at least the most radially inner working pair are advantageously hybrid reinforcements consisting of a combination of an aliphatic polyamide and an aromatic polyamide.
• the most radially inner binappe having the widest axial width has the most mechanically stressed axial ends, hence the interest of using, for the working layers of this working bin, hybrid reinforcements which present the both the advantages of an aliphatic polyamide and those of an aromatic polyamide: high breaking strength, high tensile deformability and low mass.
• the tire comprises a hooping reinforcement, comprising at least one hooping layer comprising reinforcements, embedded in an elastomeric material, forming, with the circumferential direction of the tire, an angle at most equal to 5 °, at least one shrinking layer being radially inner to the most radially inner working bundle and having an axial width at most equal to 0.8 times the axial width of the most radially inner working bin.
• the hooping reinforcement is a reinforcing reinforcement centered on the equatorial plane of the tire and consisting of at least one hooping layer comprising reinforcements, embedded in an elastomeric material.
• the reinforcements usually textile, form, with the circumferential direction of the tire, an angle at most equal to 5 °, that is to say are substantially circumferential.
• the axial width of the hooping reinforcement defined by the axial width of the widest axially shrinking layer, is at most equal to 0.8 times the axial width of the most radially inner working bundle, that is to say to say at a limited axial width compared to that of the frame of work.
• a hooping layer is radially inner to the most radially inner working bin.
• a shrink layer may also be radially external to the working frame, that is to say to any working layer, or radially interposed between two consecutive working layers.
• the tire usually comprises a protective armor comprising at least one protective layer, radially external to the armature and whose function is to protect the armature against mechanical attack of the tread.
• At least one protective layer preferably comprises metal reinforcements, embedded in an elastomeric material.
• - Figure 1 half-sectional view of the crown of a pneumatic tire of the state of the art, in a radial plane (YZ) passing through the axis of rotation ( ⁇ ') of the tire.
• - Figure 2 half-sectional view of the top of an aircraft tire according to the invention, in a radial plane (YZ) passing through the axis of rotation ( ⁇ ') of the tire.
• - Figure 4 perspective view of a strip, constituting a working bin of an aircraft tire, wound circumferentially zigzag, according to a periodic curve, on a cylindrical laying surface.
• - Figure 5 developed view of a strip, constituting a working bin of an aircraft tire circumferentially rolled zigzag, according to a periodic curve, after the laying of a period.
• FIG. 1 represents, in a radial plane YZ passing through the axis of rotation YY 'of the tire, a half-view in section of the apex of a pneumatic tire 1 for aircraft of the state of the art, comprising a working armature 2 radially inner to a tread 3 and radially external to a carcass reinforcement 4.
• the working armature 2 comprises five working pairs 21, the most radially inner working bin having the largest axial width L T , measured between its two axial ends.
• FIG. 1 only half a width LT / 2, between an axial end E of the most radially inner working bin 21 and the equatorial plane XZ, is shown.
• Each working bin 21 consists at least in part of two radially superposed working layers (211, 212) (see FIG. 3).
• Each working layer (211, 212) comprises textile reinforcements of aliphatic polyamide type, coated in an elastomeric material.
• the carcass reinforcement 4 comprises a superposition of carcass layers 41.
• Each carcass layer 41 comprises textile reinforcements of aliphatic polyamide type, coated in an elastomeric material, and forming, with the circumferential direction XX 'of the tire, an angle at least equal to 80 ° and at most equal to 100 °.
• the tire 1 comprises a protective armature 8 constituted by a protective layer.
• the working frame 2 represents, in a radial plane YZ passing through the axis of rotation YY 'of the tire, a half-view in section of the top of a tire 1 for an airplane according to the invention, comprising a reinforcement of work 2 radially inner to a tread 3 and radially external to a carcass reinforcement 4.
• the working frame 2 comprises three working pairs 21, the most radially inner working bin having the largest axial width LT, measured between its two axial ends E.
• a half-width LT / 2 between an axial end E of the radially inner working bin 21 and the equatorial plane XZ, is represented.
• Each working bin 21 is constituted at least in part by two radially superposed working layers (21 1, 212) (see FIG. 3).
• Each working layer (21 1, 212) comprises hybrid reinforcements consisting of a combination of an aliphatic polyamide and an aromatic polyamide.
• the carcass reinforcement 4 comprises a radial superposition of carcass layers 41.
• Each carcass layer 41 comprises hybrid reinforcements, consisting of a combination of an aliphatic polyamide and an aromatic polyamide, and forming, with the circumferential direction XX 'of the tire, an angle at least equal to 80 ° and at most equal to 100 °.
• the tire 1 comprises a hooping frame 7, comprising a shrink layer comprising reinforcements, embedded in an elastomeric material, forming, with the circumferential direction (XX ') of the tire, an angle at most equal to 5 °.
• the shrinking layer is radially inner to the radially innermost working bundle 21 and has an axial width Lp at most equal to 0.8 times the axial width LT of the radially innermost working bundle 21.
• axial width Lp / 2 of the shrink layer is shown.
• the geometric profile of the radially innermost working bundle 21, at its axial end E is less plated on the carcass reinforcement than in the case of the tire of the state of the shown in Figure 1.
• the tire 1 comprises a protective armature 8 constituted by a protective layer.
• FIG 3 is a detailed sectional view of the axial end of the working frame 2 of an aircraft tire 1 according to the invention, in a radial plane YZ passing through the axis of rotation YY ' of the tire.
• the working armature 2 comprises three working pairs 21, the respective axial ends of which have extra thicknesses.
• Each working bin 21 consists of two working layers (211, 212) radially superimposed in the current zone and three working layers in the axial end zone.
• Each working layer (211, 212) consists of the axial juxtaposition of strips 9, each strip being itself an axial juxtaposition of textile reinforcements 5 embedded in an elastomeric mixture.
• the textile reinforcements are hybrid reinforcements consisting of a combination of an aliphatic polyamide and an aromatic polyamide.
• the carcass reinforcement 4 comprises a radial superposition of carcass layers 41, each carcass layer 41 comprising hybrid reinforcements consisting of a combination of an aliphatic polyamide and an aromatic polyamide, and forming, with the circumferential direction XX tire, an angle at least equal to 80 ° and at most equal to 100 °.
• the distance D between an axial end E of the radially innermost working bin 21 and its orthogonal projection I on the most radially outer carcass layer 41 is at least 8 mm and the distance D ' between the point F of the radially innermost working bundle 21, axially inner to the axial end E at a distance L equal to 25 mm, and its orthogonal projection J on the radially outermost carcass layer 41 is at most equal at the distance D, and is such that the angle A equal to atan [(D-D ') / L] is at least equal to 12 °.
• FIG. 4 is a perspective view of a strip 9, constituting a working pair of a tire for an airplane, circumferentially wrapped in zigzag, according to a periodic curve 6, on a cylindrical laying surface 10, of revolution about the axis of rotation ( ⁇ ') of the tire, having a radius R.
• Figure 5 is a developed view of a strip 9, constituting a working binappe of a tire according to the invention, wound circumferentially zigzag, according to a periodic curve 6, after the laying of a period .
• the strip 9 is placed on a cylindrical surface 10 of circumference 2LTR, represented in developed form.
• the mean line of the strip 9 follows a periodic curve 6, forming an angle B with the circumferential direction XX '.
• the inventors have realized the invention for a tire for an aircraft of dimension 46X17 R 20 whose working frame comprises 3 radially superimposed working pairs. They compared a reference tire and a tire according to the invention, both having a working frame comprising 3 radially superimposed working pairs whose reinforcements are hybrid reinforcements.
• the two tires, respectively reference and according to the invention differ in the geometric profile of the most radially inner working binappe, at its axial end, said profile being said to be raised in the case of the tire according to the invention.
• the distances D, D 'and L are measured on a radial section of the tire.
• the distance D is measured, perpendicularly to the most radially outer carcass layer, between the most radially inner point of the penultimate reinforcement of the most radially inner working pair, and the most radially outer point. the first reinforcement encountered with the radially outermost carcass layer.
• the distance D ' is measured, perpendicularly to the radially outermost carcass layer, between the radially innermost point of the reinforcement of the radially innermost working pair, axially inner to the most axially outer reinforcement of the binapple of FIG. the most radially inner workpiece at a distance of 25 mm, and the most radially outermost point of the first reinforcement encountered with the radially outermost carcass layer.
• the distance L is measured as the radius equal to 25 mm of the circle having for center the most axially outer reinforcement of the most radially inner working binappe.
• the respective performance of tires of the state of the art, taken as a reference, and according to the invention were measured according to three criteria: the temperature in the vicinity of the axial end of the most radially inner working binappe, the maximum tensile stress in the axial end reinforcements of the most radially inner working bundle on a wheel revolution, and the maximum number of cycles performed without damage during a TSO test.
• the first two criteria come from a finite element numerical simulation, assuming a stationary rolling of the tire at a speed of 10km / h. The number of cycles without damage were determined by TSO tests.
• This invention is applicable not only to an aircraft tire, but also to any tire comprising a crown reinforcement with at least one binappe obtained by a zigzag winding of a strip, such as, for example and in a non-rigid manner. exhaustive, a metro tire.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Tires In General (AREA)

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• 2014
  • 2014-04-18 FR FR1453525A patent/FR3020014B1/fr not_active Expired - Fee Related
• 2015
  • 2015-04-17 WO PCT/EP2015/058344 patent/WO2015158872A1/fr active Application Filing
  • 2015-04-17 CN CN201580020262.7A patent/CN106232388B/zh active Active
  • 2015-04-17 EP EP15716810.5A patent/EP3131762B1/de active Active
  • 2015-04-17 US US15/304,622 patent/US20170036486A1/en not_active Abandoned
  • 2015-04-17 JP JP2017505718A patent/JP2017511285A/ja not_active Abandoned

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